<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <script>

        // 出生年份
        var birthYear = prompt('请输入您的出生年份');

        var age = 2022 - birthYear;

        // var result = '您的年龄是: ' + age + '岁';
        var result = `您的年龄是${ age }岁`;

        alert(result);

    </script>
</body>
</html>